1. The Field of the Invention
The present invention relates to various client/server web application architectures that provide enhanced features for web applications running on a client.
2. The Relevant Technology
Web applications are accessed by millions of people every day over the Internet. Because of the increased simplicity of developing web applications, web applications have been developed to perform various functions such as providing news content, electronic messaging, audio and visual applications, financial applications, and so on. Typically, a user accesses a web application using a browser application on a client computer. The browser application sends requests to the server hosting a web application to return the desired web document code for display by the browser application. Because a server can respond to thousands of requests almost simultaneously, thousands of users can simultaneously use the web application hosted by the server.
However, because a network can be handling thousands of requests at any given time, users can experience latency in receiving data from the server. Attempts have been made to decrease the latency in network response. One method for reducing latency is to cache or prefetch web documents in a browser cache at the client. However, local caching has historically been most efficient when the web documents are limited to text and graphic content. Furthermore, a browser cache is not secure and thus, caching user-identifiable information such as address auto-complete lists or electronic messages has been discouraged. Another method for attempting to reduce latency in web application operation is to place one or more local proxy servers between the server and the client. A local proxy server stores web document code in cache and returns the web document code to a client upon the client's request. However, again, a local proxy server is most efficient for caching static web pages containing mostly text and images.
Where web applications are increasingly relying on dynamic web content that usually resides at the server, a client must still communicate with a server to access the dynamic web content. Likewise, a local proxy server must still make a request to the server for this information before the local proxy server can return a properly generated web document to the client. When information from the server has been required, e.g., from a database stored on the server, access to information on the server has typically been accomplished by causing a web application to initiate a common gateway interface application at the server. Alternatively, a web application may include script, such as a Java servlet. In these situations where the web application must access information at the server, proper operation of web documents on a client relies on a working network connection between the client and server. Even where a local proxy server exists, when the local proxy server becomes disconnected with the server, it is unable to adequately function to provide a working web site.
Further, in many cases when operating a web application, it is desirable to be able to access local data pertaining to the same digital content that the web application is configured to handle. For example, for a web application that manages digital photo processing, a user would find it beneficial to use the same functionality on digital photos stored locally at the user's computer. However, the user is generally required to upload digital photos to be stored remotely at the server that hosts the web application in order to be able to view and manipulate the digital photos within the web application.